The invention relates to telephone attachments and more particularly to an attachment fitted over the keyboard of a pushbutton telephone for converting from the telephone pushbutton format to a calculator pushbutton format without affecting telephone operation.
The calculator pushbutton format is widely used in the manually operated keyboards of adding machines and hand-held electronic calculators. Many users of such keyboard machines become accustomed to the calculator pushbutton format through continued usage. Because the telephone keyboard is arranged in a different format than the calculator keyboard, such persons often experience mistakes in telephone dialing due to their more habitual use of the calculator format. For these telephone users it would be desirable to make available a calculator pushbutton format on the standard pushbutton telephone.